Allow Turning from None-Lanes / Consider Target Road Lanes

[MoKob]

The none tag for lanes, while technically correct, is hard to handle in osrm backend.

At some situations, the none simply represents straight -- e.g. here--,

at other locations it is possible to take a left/right turn and go straight -- e.g. here.

To be able to handle the tag correctly, we need to incorporate the number of available lanes at the destination road to compare it to the number of lanes in the turn.
If the number of lanes in the turn is smaller than the available lanes at the destination and the turn is directly next to a none tag, we should be able to augment the number of possible lanes to turn from.

This requires further investigation, though, since I am not sure if we can accurately capture all allowed cases and distinguish them from cases where it might be forbidden.

The drawback if we don't handle these cases: single lanes (like in the second example) would be completely excluded from our lane guidance. The example at the Kurt-Schuhmacher-Damm would end up never recommending the middle lane at all.

[MoKob]

Part of the work (having lanes available at all) is already done in #2779.
It would be easier to have #2779 merged before starting on this task.